Digital photography

PORTRAITS 99

BOKEH

In portraiture more than in any other genre of
photography, the quality of the blur in the
out-of-focus parts of the image—the bokeh—is
vital to the picture’s success. Whether you expose
with maximum depth of field or not, it is usual for
the majority of the image to be rendered blurred.
If the lens creates blurs that do not blend
smoothly with each other, but instead create
distinct disk-shaped blobs of color, the result is
very distracting. Good bokeh produces a fuzzy or
feathered blur, even at high-contrast junctions. At
full aperture, virtually the entire image is composed
of blur, so if you intend to use a portrait lens at
full aperture it is vital that its bokeh is good, and
that is usually a product of top-class design and
construction—in other words, an expensive lens.

▶ Breaking rules

Less than half the face is visible here, the eyes can’t be
seen, and the hair is obscured. Yet the strong character
and beauty of the subject is apparent. That is thanks to
the inclusion of the accessories: the chic hat, fashionista
shades, and expensive clothes. An image may break the
rules yet still deliver an effective portrait.

▲ Transitional mystery ▲ Editorial accuracy

Portraits are most interesting when they do not tell the Newspaper and magazine markets are the hungriest for
whole story, and when they raise more questions than good portraits. There is a constant demand for images
they answer. In this image, the contrasts between the that depict personalities in an attractive but accurate way
refined clothing and the prosaic background, the strong in an atmosphere or context that is appropriate to the
shadow, and the cool color tones all intrigue, yet the feature article or interview. Here the out-of-focus highlights
whole is visually appealing. frame the profile effectively and sympathetically.

100 PHOTOGRAPHY PROJECTS

PORTRAITS CONTINUED

intend to distort your subject comically. On the you are commenting on their relative power in that
other hand, being able to get so close to someone context: you could have shown them dominant in
suggests trust and intimacy, so that can be a useful the same space. The environment and person
signifier to exploit. reciprocally contribute significance to a portrait.
The following points are also worth bearing in mind:
It is hard to go wrong if you focus on the eye ▪ Locating the sitter in the center of the image
nearest the camera, particularly if you are using a signifies that they truly are intended to be the
large aperture (f/2 or greater). This forces attention center of attention, even if they are small in relation
on the all-important eye, while painting the rest of to the background.
the scene with broad, blurred brush strokes. If your ▪ Locating the sitter to one side suggests that
camera uses multiple focusing points, it is easiest if atmosphere, mood, or the environment is just as
you set it to use the focusing point over or nearest important as the person, particularly if they are
to the eye. It always helps to ensure there are no small relative to the background.
highlights or specular reflections in the background, ▪ If you are working in color, pay particular attention
unless it is an important part of the scene—a desk to colors of objects in the background: they can
lamp or the setting sun, for instance. contribute information and visual interest, or they
can tear the image apart. Intense, hot colors are
Environmental impact distracting, as are bright highlights and shiny objects
with strong, geometrical shapes. Movement blur in
By making portraits outside the studio, you can take the background is also distracting.
full advantage of your sitter’s environment—their ▪ Compositional techniques such as converging
living or working space—as part of the observation lines and framing devices, such as doorways or tree
about the person. Remember that the size of the branches, help direct attention to your sitter.
person in the image relative to the space shown is ▪ Shallow depth of field with a varied background
intuitively proportionate to the importance of works well to bring the sitter forward visually.
the context to the person’s life. For example, if you
make someone appear small in their work space

◀ Team work

Group photographs may
concentrate on the team, in
which everyone is equally
important: the photograph
is really about the team
as a whole and is best
composed as such. Or
groups may be made up
of individuals: it is part of
accuracy in visual language
that the composition
reflects the dynamics of
the group of people. Here,
each person is shown
relaxing in different ways,
paying varying levels of
attention to the
photographer, all held by
the receding lines and
repeated chairs.

PORTRAITS 101

▲ Grace under fire rendered in black-and-white, we can concentrate on the
dancer who is framed by the geometric shapes around her.
Even when exhausted from hard training in stifling hot Unfortunately, the light behind her head is too bright to be
welcome, but this can be easily removed digitally.
conditions, this dancer holds herself with peerless elegance,

surrounded by the paraphernalia of her studio. Greens,

browns, and pinks in the scene were too distracting, but

▲ Handyman ▲ Keep it simple

While the face is the most emotional and evocative part For many purposes, such as small business websites,
of the body, telling much of the story, it does not tell the pamphlets, and picture albums, the straight-forward posed
whole story. Hands, feet, hair, and arms can all contribute. shot remains the best option. A smile and an example of
In the case of working hands, they may be able to tell the the product in the context of the business is the kind of
story by themselves. You usually have to work in low light, image that is equal to a thousand words. Shoot such images
so prepare your settings—high ISO and large aperture for in flat lighting, with centered composition with a normal or
short exposure time—then approach closely and observe. moderately wide-angle lens.

102 PHOTOGRAPHY PROJECTS

CAMERA PHONE PHOTOGRAPHY

▲ Project compilation The cameras built into modern cell phones
comfortably surpass the quality and capability of
As image quality is more than acceptable in many camera early digital cameras. By combining utmost
phones, there is no reason not to use them for photography convenience—you always have a camera with you
projects. They are especially useful for ongoing projects, because you always carry your phone with you—
where you need to keep a camera with you at all times, with fair- to good-quality imaging, camera phones
such as capturing a variety of weather conditions, collecting have become the most widely used type of camera.
interesting cloud formations, or cataloging landforms. It is worth noting that the companies making the
If you need to make wide-angle views, you can take most cameras (by a very large margin) are, in fact, in
overlapping shots that you then stitch together as the business of making phones.
if making a panorama (see pp. 190–1).
Bare necessities

One of the main attractions of camera phone
photography is that you are forced back to the very
basics: with minimal controls, you have no choice
but to concentrate simply on picture-making. Some
camera phones allow digital zooming, some offer
touch-screen choice of focus point and exposure,
and many allow images to be shot in various modes
such as vintage (usually sepia), or with filter effects
applied, either after normal capture or as part of
image processing (see pp. 156–7). But simplicity is
the overriding virtue.

Bare technique

For all its simplicity, you can help your camera
phone to produce superior results. The Achilles heel
of the camera is the tiny lens: because it is so small,
even the smallest smudge or smear will reduce the
quality of the image. Use a microfiber cloth to keep
the lens scrupulously clean.
▪ Hold the phone steadily during exposure:
squeeze or tap gently for the shot.
▪ Give the sensor plenty of light to work with: low
light produces noisy images.
▪ Give the camera time to focus: camera phones
cannot focus as quickly as larger cameras.
▪ Use features that give more accurate focus or
exposure control; for example, on touch-screen
camera phones such as the iPhone, touching on the
image shifts the focus and exposure determination
to that part of the scene.
▪ The flash on camera phones is very weak and is
effective only to about 6ft (2m). Turn it off for more
distant objects.

▲ Visual notebook attach GPS and other data to images increases their value
for documentation. And, despite everyone being familiar
Camera phones are the ultimate visual notebook: you can with phones being used as cameras, a camera phone attracts
much less attention than even a compact camera.
use them to snap images of captions in exhibitions, make

visual notes of items of furniture or objects for interior

design, or to help document a house-hunt. The ability to

▲ App effects DIGITAL HUB

There are a number of applications available that allow you The modern cell phone is also a camera that
to apply effects to your camera phone images. Some, such can make calls and connect to the world. Images
as Instagram, apply the effect to a normally captured image. captured on a camera phone are easy to send
Others, such as Hipstamatic, apply the effects as part of the around the world to social-network sites such as
capture process. This commits you to the effect and is a Facebook to be viewed by friends, upload to
challenging and refreshing way to work. picture-sharing sites such as Instagram or Flickr,
or attach to an email or text message.
▪ Ensure the orientation of your images is correct

for its intended use before sending them out.
▪ Resize the images to no larger than 640 pixels

on the longer side for quick transmission (if
that option is available).
▪ If you are not in your home country, sending
images can be expensive. Check with your
service provider to ensure that you do not
exceed your data limit.



3 IMAGE
DEVELOPMENT

106 IMAGE DEVELOPMENT

WORKFLOW ESSENTIALS

Digital workflow is similar to processing black-and- images is when all the details of the shoot are fresh
white film in that there are efficient ways and less in your mind and you know where, when, how, and
efficient ways of working. And just like film why you made the images. This is when crucial
processing, an error can reduce the quality of your tagging data and notes should be appended to the
images, or even ruin them. The big difference is in image. Following the sequence below will give you
the numbers of images you can work with: now you an efficient and time-saving workflow:
could have thousands of images after a wedding. ▪ Ingest: on your computer, create a new folder
It is important to avoid having to spend hours in named by subject, date, or location, and upload
front of the computer wading through them. A little your images into this. Add metadata such as subject,
time planning a workflow will save days over date, location, and copyright to each image. If
the course of a year. necessary, you can rename the images with
sequential numbering. Finally, you should back up
Horses for courses the images to a secondary disk.
▪ Inspect: check the technical quality of a sample
It makes sense to match the flow of images to of your images. Ensure that they are sharp, well-
suit the project. If you shoot for yourself, a plan exposed, and have accurate white balance. If your
that fine-tunes one image at a time is fine: this is camera does not turn images that you have shot in
how it was done in the early days of digital portrait format to the upright orientation, you
photography. One simple plan is to set up
your camera so that you can use the images
immediately—on photo-sharing and social
networking sites, or for printing out—without any
post-processing. This workflow is almost effortless
and all that is needed for many users. It is only when
you want higher quality and more control that the
extra effort is justified.

Soft options

One of the key decisions you need to make
is whether to use the same software application—
such as Google Picasa, Adobe Photoshop
or Lightroom, ACDSee, or Apple Aperture—to
manage and correct your images throughout.
Lightroom, ACDSee, and Aperture treat all
images nondestructively, operating only on proxy
files. Alternatively you can use a different
software package for each task—for example, Photo
Mechanic for managing files, then Adobe
Photoshop Elements for manipulation. Match the
type of software and its cost with your needs.

Basic steps ▲ Plain sailing

The principle of workflow is to minimize time at the In the early stages of editing images, you may have wildly
computer by never duplicating work unnecessarily differing images to choose from. Leave the final selection
and ensuring that at any time in the future, it will be until you have become very familiar with the shoot. Making
easy to find an image. At the time you upload your tonal and color adjustments is easiest with proxy-working
software such as Lightroom, Aperture, and ACDSee.

WORKFLOW ESSENTIALS 107

should do that now. If any of the images appear ▪ Final effects: apply any drastic changes, such as
corrupted, upload them again. conversion to black and white or sepia. Leave noise
▪ Evaluate: locate the first choices, second choices, reduction to this step; apply sharpening, if required.
and reject images, and apply ratings to rank them. ▪ Prepare: if you used layers, use Save As to keep
▪ Apply metadata: write information-rich the layered image in case you wish to modify the
captions. Make sure that you add identifying tags corrections you applied. Prior to export, flatten the
and other descriptive keywords. image, resize it, and save it in the required format.
▪ Set up: create a new folder for work in progress. ▪ Use: export directly to the target destination; for
Save images with new filenames if you are making example, from Lightroom straight into your
changes to the original files. Use a storage device Facebook page. If you cannot export directly, create
different from that holding the original image. a transit folder for exports.
Straighten, crop, or resize images as required. ▪ Archive and tidy up: Make backup copies of
▪ Enhance: normalize the blacks and highlights new files on hard disks. If you have created any
with exposure and curve correction. folders for temporary files or files for download,
▪ Soft proof: check how the image will look when remove them from your main machine. Double-
outputted by reviewing proof colors. Adjust the check that you have two copies of images from
image settings as required. your memory cards, then reformat the cards in your
▪ Clean up: remove any flaws such as dust spots. camera so they are empty and ready to use.

▲ Drastic changes

Substantial image changes, such as layering a sunset with
a mid-afternoon scene, should be made on a copy of the
original file. Work at full resolution even if you need only
a small final image: perhaps one day someone will want
to use the image large, having seen it on your website.

108 IMAGE DEVELOPMENT

DOWNLOADING

Like it or not, the center of your photographic work
is the computer. It is crucial to download images
captured on your camera to hard disks under the
control of the computer, as you can then back up
and work on the images. Then, when images are
ready to be used, you will upload them from your
computer to picture sites or into emails.

Computer bypass ▲ Bit error

However, there are ways to avoid using the computer. Errors in the memory card or occurring during download
You can download images from a memory card
directly to a portable storage device that combines cause a break in the sequence of data, so part of the image
a hard disk drive with a card reader. Also, you can
send images from camera phones directly to social looks fine but the rest is corrupted. Download it again to
networking sites. Cameras equipped with Wi-Fi can
connect to the internet and upload images to isolate the error: if it recurs, the memory card is at fault.
distributed networks—this is popularly known as
Cloud computing. Having logged-on to your cloud
account using, for example, Google Docs, Dropbox,
or Box.net you can upload your images to the
storage space in your account. Sooner or later,
however, the images will need to pass through your
computer. One reason for this is security: your
digital images are safe as long as you keep copies in
different places at the same time.

Quick download ▲ Incomplete scan

The fastest way to download images is to remove If data recording or downloading was interrupted for some
your camera’s memory card and use a card reader reason, this results in a blank area. The preview may be
connected to your computer via USB 3.0, Firewire visible but the full file may not open at all. The memory
800, or Thunderbolt—whichever is your fastest card may be faulty or the download might need repeating.
connector. You can connect your camera directly
but if you have multiple cards, it saves wear and tear ▲ Auto correction
on the camera to use a dedicated card reader.
Images may be corrected automatically by the camera
The key to keeping your images safe is to when they are saved or downloaded. If there was a serious
download the pictures—as soon as possible—to error at the time of capture, the image may appear but be
your computer’s hard drive or a mounted drive, seriously degraded, but the file itself is not faulty.
leaving the images on the memory card. When you
can, copy the images to another hard disk, or DVD
or Blu-Ray disk; then they will be in three different
places and pretty safe from loss. If you are working
wirelessly and subscribe to services such as Apple
iCloud or Adobe Carousel, then upload to these
services. Only when you are sure your images are
backed-up should you reformat the memory card.

DOWNLOADING 109

▲ Choosing color mode

An image’s color mode is crucial to the success and
quality of manipulation. RGB is useful for most image
enhancements, but it is not the only mode. LAB is less
intuitive to understand, but it is most flexible and versatile
when preserving color data to maintain image quality is a
high priority. Here, the initial RGB capture underwater
(above) was low in contrast and carried an overall green
cast. If left in RGB, Auto Levels correction gives it a bright,
colorful, but not accurate result (above right). In LAB mode,
Auto Levels correction produces true-to-life colors with
accurate tonality (right).

CHECKING THE IMAGE ▪ Is the white balance accurate? If the file is not in
RAW format, corrections may cause inaccurate
▪ Check the color mode and bit depth. Files colors and tones.
from scanners may be saved as LAB files. Most
image-manipulation software works in 24-bit ▪ Are the colors clear and accurate? If not,
RGB color, and if the image is not in the correct corrections may cause posterization, stepped
mode, many adjustments are unavailable or give tonal changes, or less accurate hues.
odd results.
▪ Check that there is no excess border to the
▪ Check that the image is clean—that there are no image. It may upset calculations for Auto Levels
dust spots or, if a scan, scratches or other marks. or other corrections.
Increasing the contrast of the image and making
it darker usually helps to reveal faint dust spots. ▪ Check the file size. It should be adequate for your
purposes but not much larger. If it is too small,
▪ Ensure that the image has not had too much you could work on it for hours only to find it is
noise or grain removed. not suitable for the output size desired. If it is too
large, you will waste time as all manipulations
▪ Assess the image sharpness. If the image has take longer than necessary.
been overly sharpened, further manipulation
may cause visible edge artifacts. ▪ Check the color profile for the image: for general
purposes, use sRGB; for demanding uses, set
▪ Is the exposure of your pictures accurate? If not, Adobe RGB (1998).
corrections may cause posterization or stepped
tonal changes.

110 IMAGE DEVELOPMENT

IMAGE MANAGEMENT

Whether you are a casual, amateur, or professional a leaflet, must be text-based. Metadata or tags (also
photographer, your photographs represent a called soft data) are descriptive words, names, and
considerable investment. It is not just the cost of the other data added to or embedded in an image.
camera and the computer equipment, but also the
time spent learning how to use the equipment and We find an image of Cape Town, for instance,
software, not forgetting the time spent on chasing not by examining millions of images on the lookout
photos. And, no false modesty here, there is also the for features belonging to South Africa’s great city,
valuable input of your artistry and skill. but by first looking for images carrying the name
tag “Cape Town.” What is more, you might have no
There are two sides to managing your idea what Cape Town looks like, yet you can collect
photographic assets. One is ensuring that you do dozens of excellent shots merely by searching for
not lose any, and that they last forever. The other is the tag. In fact, any image failing to carry the tag is
to make them easily available—at least to yourself very unlikely to be found, even if it is the best
and, at best, to anyone who wishes to use them. possible shot of the city.

Safety in numbers The addition of metadata is an essential skill.
Minimally, metadata should identify the subject or
In the current state of technology, no digital medium event, the date, the location, the copyright holder,
can match film-based images for archival safety— and the photographer. The information should be
the ability to survive unchanged and easily used for enough for anyone to know for sure what the
more than a hundred years. Those who would like picture is about and to be able to contact you, so it
their legacy to stretch into the next century or two should carry a caption and your details. In addition,
may be best advised to return to shooting on film. keywords that refer to key elements of the image
For the more modest, the best strategy is to keep and a unique identifier, such as a serial number, can
digital image files in multiple storage systems and in help anyone to locate your image.
multiple places. For small numbers of images, use
DVD or Blu-Ray disks to archive your images, even Caption marvel
though these are slow to write and access. Hard
disk systems are much better for working with, but The rule for an effective caption is simple: answer
are less reliable (see p. 216). the what, when, where, and who questions. Many
agencies have a limit to the number of characters
Hard disk systems called RAID (redundant array you can use, so it takes some skill and planning to
of independent disks), which allow for the failure of get down all the information in the space available.
one or more disks without any loss of data, are now While keywords are essential in helping a potential
affordable to anyone who takes photography user to locate your photograph, the caption may
seriously. They may cost as much as an SLR, but clinch the deal as it can confirm the exact details
they are arguably more important than an extra and timing needed.
camera if you value your photos. The RAID’s
contents can be backed up on inexpensive desktop Start today
drives that are kept in different locations—for
example, at a relative’s house. It may seem unnecessary to organize a collection of
a few hundred images, but it is an easy task, and
Soft gold you will learn through the process. If you start
when you really need to—with a collection of
The total number of pictures on the internet is thousands of images—the task could be
climbing well beyond a trillion, thanks to your discouragingly onerous. So your most important
contribution among several hundred million other decision is to decide to start right now, before you
photographers. Locating a particular image, for lose any precious images in a hard disk crash and
example, to illustrate a magazine feature or use on long before it is really necessary.

IMAGE MANAGEMENT 111

CALLING NAMES ▪ File names are most easily changed at download
time or renamed in a batch.
▪ There are two main ways you can name your
images. You can use the names given by the ▪ If you create specific names, keep a running
camera, usually a generic DSC1234 or _IMG1234. catalog to ensure that each is unique—for
(The underscore prefix means that the embedded example, by job number or date.
profile is Adobe RGB.) Alternatively, you can name
files more specifically. Professional users will ▪ Camera-generated names usually repeat after
benefit most from using specific image names. 9,999 images.

◀ File lists

Image files can be shown
in lists that display a
thumbnail of the image
together with all its
associated metadata.
Selecting one of the images
allows the metadata to be
edited. In software such as
Apple Aperture (shown
here) or Adobe Lightroom,
image-enhancement
controls are available
alongside tools for
organizing material for
slide shows, web pages,
or books.

◀ Management
software

One of the best ways to
organize your images is
to use management
software. Applications
worth considering include
Adobe Lightroom, Apple
Aperture, Extensis Portfolio,
ACDSee, and Camera Bits
Photo Mechanic (shown
here). Not only do all these
programs help you to keep
picture files organized, they
can also create “contact
prints” and slide shows, as
well as publishing picture
collections to the web.

112 IMAGE DEVELOPMENT

CAPTURE DEFECTS

There is a story about a group of great photographers color. The other defects result from inadequacies
who decided to make a list of what could go wrong in technique, such as poor focus or exposure,
in photography. They gave up when they reached camera shake, and unwanted distractions—such as
200 items. The defects highlighted here are only the an object sticking out of a subject’s head, or
common errors that are easy to miss—some even telephone wires across the sky.
for the experienced photographer—leaving out
the obvious such as poor focus or camera shake. To varying degrees, all defects can be corrected
or hidden: this is one of the glories of digital
Original sins photography. However, you will find that you save
yourself a great deal of time and frustration at the
There are two kinds of image defect: those arising computer by taking utmost care when capturing
from inadequacies of equipment such as poor the image. Your ultimate aim is never to have to
image quality, flare, noise, and problems with manipulate an image to make it usable.

▲ Distractions ▲ Highlight clipping

Some distractions may be avoided altogether through When overexposure causes highlights to lose all color and
careful choice of position and framing, but wires and cables detail they are said to be clipped. It is impossible to recover
that stretch between buildings, spoiling the view of the sky, these areas, so they are best avoided altogether. Recording
are notoriously difficult to avoid. Treat them as an image in RAW format and bracketing exposures for tone
defect, whose removal is part of post-processing. compression (see pp. 168–9) may help.

▲ Noise ▲ Shadow clipping

When visible, irregular spots of color or large “clumps” of The opposite of highlight clipping (above) is loss of detail
light or dark pixels disrupt image detail and color. Noise is and color in shadows due to underexposure. It is usually
commonly blamed on sensor performance, but can also be easier to extract some detail and color from clipped
made apparent by post-processing; it is the price you pay shadows than from clipped highlights. Recording in RAW
for rescuing underexposed images. (see pp. 158–61) increases the chance of a successful fill.

CAPTURE DEFECTS 113

Avoid if possible WORSHIPPING QUALITY

Certain defects are impossible to correct fully. If a Image quality is usually overrated. While the
lens hood for a wide-angle lens is misaligned it will combination of a stunning image with technical
cause shadowing or vignetting in the corners: the perfection is a very fine thing, it is a common
only way to remove them is to crop the image. The mistake to focus on quality alone. Remember
same applies to tilted horizons. Flare caused by that many of the greatest pictures in the history
pointing the camera at the sun can be extremely of photography were made on equipment and
troublesome to remove or disguise. And, of course, film far inferior to even today’s amateur cameras.
poor focus leads to loss of details that cannot be But no one complains about their grain or poor
recaptured. However, some unsharpness or blur color. Concentrate on making a wonderful image;
resulting from movement can be reduced using quality comes a long way behind.
modern algorithms.

▲ Tilted horizon ▲ Excessive depth of field

This problem is commonly caused by cameras that are A common problem arising from the widespread use of
heavier on one side than the other, also by using small live small sensors, too great a depth of field gives too much
image screens. A tiny tilt looks like an error, but very obvious prominence to the background, distracting the viewer
tilts look deliberate and can be acceptable. Correcting the from the main subject. Use post-processing to blur the
tilt is easy but always involves cropping. background selectively (see pp. 130–3).

▲ Leaning verticals ▲ Unbalanced color

Tilting the camera up to take in the full height of a building Until more cameras use intelligent white balancing, a
usually causes the building to look as if it is leaning back common defect is the inaccurate capture of neutrals in the
awkwardly. This often looks like poor technique. But tilting presence of a strong illuminating color, such as here, where
up strongly is often accepted as a deliberate visual effect. the red candles cause the white walls to look blue. This may
Small amounts of lean can be corrected. need careful, hue-specific correction (see pp. 136–9).

114 IMAGE DEVELOPMENT

COLOR MANAGEMENT

The aim of color management is to control the manually because a number of variables (gamma,
imaging chain so that between the subject, white point) need to be set by the operator.
its captured image, the image displayed on a
monitor, and any of its printed forms, there is the Monitor calibration
least possible variation in appearance. The key
strategy is to define the behavior of each component There are software-based methods for calibrating
in terms of a common standard, known as the monitors and hardware-based methods. The
profile connection space. former is free but less accurate than the latter,
which you have to purchase, but prices are now
Digital color management a fraction of what they used to be. CRT (cathode
ray tube) monitors should be warmed up for
The central problem is that the color gamut or 30 minutes before calibration, and should be
range of reproducible colors of different devices recalibrated at least once a month. LCD monitors
vary considerably. It is easy to make a set of need less warm-up time, but should also be
adjustments that ensure our images appear on our recalibrated regularly.
monitor as they print out: this was what the old
Adobe Gamma control was used for. But we might After calibration, a profile for the monitor is
change our printer or update our camera: each created. This should be used as the monitor profile.
time we make a change—even of paper type—we In addition, you need to ensure that your work
need to make new adjustments. takes color management into account. This profile
can be set as the output space or applied to the
The solution is to use a common color space— viewed image directly. Applying an output profile
essentially that which can be seen by the eye—to usually makes the image look duller, but it should
describe how the color reproduction of a correctly be a close match to the print.
set up device differs from the standard. This
generates the device’s profile. Note that the Viewing conditions
device must be correctly set up: this is the task of
calibration. Cameras and printers are essentially It is useful to consider the features of ideal viewing
self-calibrating, but monitors need to be set up conditions, if only to make you realize how far your
own conditions fail to reach them. Walls should be

CALIBRATION ▲ On-screen ▲ Linear gamma ▲ 1.8 gamma
calibration
Using the most accurate With the screen set to The 1.8 gamma was
monitor calibrators or On-screen calibration Linear Gamma, the overall formerly the default setting
using on-screen targets offers prompts such as result is very bright, blacks in Apple Macs and the print
will be of little help the above, showing steps are gray, and colors look industry. It is now regarded
if the basic settings for for setting luminance washed out. Images as too bright compared to
gamma and white point response curves and the adjusted on this screen the 2.2 gamma standard
are not carefully chosen balance between the would look too dark, on Windows machines. A
to suit the end use of three colors. Settings are saturated, and contrasty on gamma of 2.0 may be set
your images. If you altered to match targets. normally adjusted screens. as a compromise.
supply to third parties
such as stock agencies,
magazines, or printers,
consult them to find
out their preferred
monitor settings.

COLOR MANAGEMENT 115

painted white or a mid-tone neutral gray. Curtains The monitor should be hooded against local light
should not be colored, that is, they should block sources such as desk-lamps.
out the light without filtering it—neutral colored
blinds are best. Light levels in the room should be Ideally, prints should be viewed in standard
constant, and preferably only bright enough to daylight viewing booths and transparencies should
allow you to find your way around the room— be viewed on standard light-boxes, placed as close
around 4 lux is ideal—and those parts of the image to the screen as possible. Booths should comply
that are black should look black on screen. with ISO 3664:2000, that is, they should use the CIE
reference illuminant D50.

PROFILE RELATIONSHIPS Source profiles are seldom used
because the majority of files are
This diagram demonstrates how color characteristics processed visually and are only
of different devices can be translated to each other, of value with digital images in
using color profiles and a common color space. highly controlled environments,
such as studios.
An image file may be embedded
with a color profile so that it can Working color space is your
be accurately reproduced when starting point. The sRGB color
space is widely used for digital
it enters a different working cameras and gives acceptable
color space. results. Another standard is Adobe
RGB (1998), which gives better
Ink-jet profiles are perhaps the results for professional use.
most troublesome for keen
CMYK output profiles are
photographers. But produced important for professional users
accurately and used correctly, they and publishers of magazines and
books, but they need not concern
can help maintain reliable, the majority of photographers.
consistent results.

Monitor profiles are important because they help
the computer system control the monitor, ensuring

that colors are produced accurately.

▲ 2.2 gamma ▲ D50 target white ▲ D65 target white ▲ 9300 target white

The standard on Windows Formerly widely accepted As incandescent lights are Suitable for domestic TV
machines, indicating a high as the standard target white used less and more prints and video, where the final
level of correction to the point for a monitor—that is, are made on bright white viewing is on TV sets, this
monitor’s output. Colors the monitor attempted to paper, the D65 target white white point is generally
are rich, and blacks appear display white according has become more widely too blue for digital
solid while retaining to the definition for D50. adopted. It gives a cooler, photography. Using 9300
shadow detail but the The result appears to bluer result than D50 and is will result in images that
image quality is a poor modern eyes to be a good choice for general look too red or yellow, and
match for print quality. creamy or yellowish. digital photography. with flattened contrast.

116 IMAGE DEVELOPMENT

CROPPING AND ROTATION

The creative importance of cropping, to remove With film-based photography, this correction was
extraneous subject detail, is crucial in digital carried out in the darkroom during the printing
photography—it can even be used as a compositional stage. In digital photography, however, rotation is a
tool in its own right. A single image can have many straightforward transformation, and in some
different interpretations according to how it is software applications you can carry out the
cropped, although you should not let this affect your correction as part of the image-cropping process.
decisions when composing and framing your images.
Note that any rotation that is not 90°, or a
Not only does digital cropping reduce picture multiple of 90°, will need interpolation. Repeated
content, it also reduces file size. Bear in mind that rotation may cause image detail to blur, so it is best
you should not crop to a specific resolution until to decide exactly how much rotation is required,
the final stages of image processing, as resizing by and then perform it all in a single step.
interpolation will then be required. This reduces
picture quality, usually by causing a slight softening Correcting scans
of detail. Image cropping without a change of
resolution does not require interpolation. Cropping and rotation are also useful tools if you
are scanning old film images from your archive. For
Image rotation example, you may want to remove the border
caused by inaccurate scanning. This area of white or
The horizon in an image is normally expected black not only takes up valuable machine memory,
to run parallel with the top and bottom edges of the it can also greatly distort tonal calculations, such as
image. Similarly, you may want to make sure Levels (see pp. 120–1). If a border to the image is
that vertical lines in your image are correctly needed, you can always add it at a later stage using
aligned, particularly when photographing buildings a range of different applications.
(see pp. 55–7) or other subjects with strong
geometry. Slight mistakes in aiming the camera— Rotation can also be used to correct any
not an uncommon error when you are working inaccuracies in placement on the scanner. However,
quickly or your concentration slips—can be always check that scanned negatives are correctly
corrected by rotating the image before printing. oriented—that left-to-right in the original is still left-
to-right in the digital image.

◀ Creative cropping

Cropping can help rescue
an image that was not
correctly framed or
composed. By removing
elements that are not
required or are extraneous
to what you intended, you
can create a more visually
coherent final image.
Beware that crops to one
side of a wide-angle image
may appear to distort
perspective, since the
center of the image will not
correspond to the center
of perspective. Cropping
decreases the size of the
image file and calls on
the image’s data reserves
to maintain image quality.

CROPPING AND ROTATION 117

SAVING AS YOU GO as the computer is on and functioning properly. If
your file is large and what you are doing is
When working on image manipulations, make complicated, then the risks of the computer
sure you adopt good working practices: always crashing are increased (and the resulting loss of the
work on a copy of the original file, and get into work more grievous). A good rule to remember is
the habit of saving your working file as you that if your file is so large that making frequent saves
proceed: press Command + S (Mac) or Control is an inconvenient interruption, then you definitely
+ S (PC) at regular intervals. It is easy to forget in should be doing it, inconvenient or not.
the heat of the creative moment that the image
on the monitor is only virtual—it exists just as long

◀ Sloping horizon

A snatched shot taken with a wide-angle lens left the
horizon with a slight but noticeable tilt, disturbing the
serenity of the image. But by rotating a crop it is possible
to correct the horizon (below), although, as you can see
from the masked-off area (left), you do have to sacrifice
the marginal areas of the image. Some software allows
you to give a precise figure for the rotation; others
require you to do it by eye.

118 IMAGE DEVELOPMENT

QUICK FIX POOR SUBJECT DETAIL

Producing the sharpest possible image in most variety of techniques such as unsharp masking
situations provides the most flexibility later. You (USM). Some cameras also apply USM as they
can easily blur a sharp image, but it is very difficult record so that images appear sharper when viewed
to rebuild detail that is lost to blur. on screen. However, too much in-camera sharpening
effectively reduces the final image quality, so it is best
Problem: Images lack overall “bite,” and sharpness to apply manually controlled sharpening, viewing
the effects on a large computer screen. Monitor
and subject detail is soft or low in contrast overall. sharpening effects with your image at 100 percent
or larger while you apply them. For print use,
Analysis: Unsharp detail rendered with low sharpen until the improvement is just visible. For
screen use, sharpen until the effect is apparent
contrast can be caused by any of the following: use but no more than that (see also pp. 126–9).
of a poor-quality lens; inaccurate focusing; dust or
scratches on the lens; or an intervening surface, such A boost of image mid-tone contrast and color
as a window. Movement of the camera or subject saturation also improves the appearance of image
during exposure may also cause loss of detail. sharpness. Sharpening filters cannot retrieve details
lost by movement during exposure, but new
Solution: The core technique for improving detail algorithms can help reduce motion blur.

is digital sharpening, or increasing clarity, using a

▲ Lacking bite ▲ Clarity of detail

This snap of a bandsman lacks clean definition of detail, in By applying strong unsharp masking to the image, its

particular in the face. The shiny metal gives the impression impact is greatly improved. In particular, the musician’s

of sharpness, but that is just an illusion as a result of the eye reveals an intense concentration, probably focused

reflections and high-contrast lines. on the band leader.

HOW TO AVOID THE PROBLEM ▪ For long exposures, use a tripod or rest the
camera on some sort of stable support—such as
▪ Keep the front and back surfaces of your lens a table, window ledge, wall, or a pile of books—
and any lens filters clean. Replace filters as to prevent camera movement.
soon as they are scratched.
▪ Experiment with your lens—some produce
▪ Focus as precisely and carefully as possible. unsharp results when they are used very
▪ Release the shutter smoothly, in a single action. close up or at the extreme telephoto end of
their zoom range.
For longer handheld exposures, make the
exposure as you breathe out, just before you
start to breathe in.

QUICK FIX POOR SUBJECT COLOR 119

QUICK FIX POOR SUBJECT COLOR

If subject color is disappointing despite your
best efforts, the key to effective improvement
is to be selective.

Problem: Your images are underwhelming,

with lackluster color vibrancy and dull tones
overall. These problems most often occur in pictures
captured on overcast days.

Analysis: Your camera may make conservative

adjustments to a captured image. In addition,
light that is lacking a full range of colors—for
example, on overcast days—is weak in warm
colors, resulting in a bluish color cast that gives dull,
cold images.

Solution: A sound first step is to correct the

white balance if it is too blue or yellow. Then the
simplest solution is to apply increased saturation
to the whole image. But this often overemphasizes
some colors in the effort to make others more lifelike.
It is better to analyze the image and decide which
colors—the yellows, say—would most benefit from
improving, then limit the increased saturation to
yellows (see pp. 136–41).

▶ Selective saturation

The original image (top) suffers from dull colors. An overall
increase in saturation brings the green of the cranes back to
the remembered color, but the face of the supervisor is too
red (middle). We increase saturation limited to greens, for
the cranes; yellows, for the markings on the wharf; and
cyans, for the sky—by amounts to match needs. This allows
the skin tones to remain natural-looking (bottom).

HOW TO AVOID THE PROBLEM ▪ Set your camera’s white balance to a setting
that is appropriate to the prevailing conditions—
▪ In bright, contrasting lighting conditions, it may for example, “cloudy” on an overcast day.
help to underexpose by a small amount: set the
camera override to -1⁄2 of a stop or -1⁄3 of a stop, ▪ Avoid setting the camera to very high sensitivities,
depending on what the controls permit. such as ISO 800 or above. And if you still
work with a film camera, you should not use
▪ To avoid computer-based image manipulation, high-speed color film of any type if color
try using camera modes that boost image accuracy is crucial.
saturation. These are typically called something
like Landscape, Brilliant, or Vivid.

120 IMAGE DEVELOPMENT

LEVELS

The Levels control shows a representation, in the Another control that may be available is Output
form of a histogram, of the distribution of tone Level. This sets the maximum black or white
values of an image. Levels offers several powerful points that can be produced by, say, a printer.
options for changing global tone distribution. The Generally, by setting the white point to at least
easiest thing to do is to click on the Auto Level 5 less than the maximum (in other words, to
button. This, however, works effectively in very few about 250) you prevent the highlight areas in your
cases. What it does is take the darkest pixel to output image appearing totally blank. Setting the
maximum black and the brightest pixel to maximum black point to at least 5 more than the minimum
white, and spreads everything else evenly between (in other words, to about 5) you will help to avoid
them. This, however, may change the overall density the shadow areas looking overly heavy in your
of the image. output image.

◀ Auto Level

An underexposed image
contains dark tones with
few high-value ones (far
left), confirmed in the
Levels display (bottom far
left). The gap on the right of
the histogram indicates an
absence of values lighter
than three-quarter tone,
with peak values falling in
deep shadow. Applying
Auto Level (left) spreads all
available pixel values across
the whole dynamic range.
The new Levels display
(bottom left) has a
characteristic comblike
structure, showing gaps in
the color data. Auto Level
not only brightens colors
and increases contrast, it
also causes a slight overall
color shift.

HOW TO READ LEVELS extreme, with few other values, you probably
have an image that is over- or underexposed.
The Levels histogram gives an instant check on image ▪ If the histogram has several narrow vertical bars,
quality—perhaps warning of a need to rescan. the image is very deficient in color data or it is
▪ If all values across the range are filled with gentle an indexed color file. Corrections may lead to
unpredictable results.
peaks, the image is well exposed or well scanned. ▪ A comblike histogram indicates a poor image
▪ If the histogram shows mostly low values with many missing values and too many pixels of
the same value. Such an image looks posterized
(weighted to the left), the image is overall low-key (see pp. 142–3).
or dark; if values are mostly high (weighted to the
right), the image is high-key or bright. These
results are not necessarily undesirable.
▪ If you have a sharp peak toward one or other

LEVELS 121

▲ Well-distributed tones ▲ Deficient color data

As you can see from this Levels histogram, a bright, An image with only a limited color range, such as this
well-exposed image fills all the available range of pixels, still-life composition, can be turned into a very small file
with no gaps. Since the image contains many light tones, by saving it as an indexed color file. In fact, just 55 colors
there are more pixels lighter than mid-tone, so the peak of were sufficient to represent this scene with hardly any loss
the histogram lies to the right of center. This image would of subject information. However, the comblike Levels
tolerate a lot of manipulation thanks to the richness of histogram associated with it indicates just how sparse the
color data it contains. available color data was. Any work on the image to alter its
colors or tonality, or the application of filter effects that alter
its color data, would certainly show up artifacts and produce
unpredictable results.

HISTOGRAM DISPLAY

The histogram for this image shows the mid-tones
dominated by green and red, consistent with the strong
yellows and browns of this warm, wood-dominated
interior. Applications can be set to display histograms
for each RGB channel
or combined, usually
as luminance for
an accurate view
of brightness.

122 IMAGE DEVELOPMENT

BURNING-IN AND DODGING

The two key techniques for manipulating the local and dodge to bring out what shadow and highlight
density of an image in digital post-processing are detail does exist by increasing local image contrast.
known as burning-in and dodging.
The same techniques can be used in order to
Controlling density reduce contrast—to darken highlight areas, for
example—to bring them tonally closer to image
Burning-in increases the density in the area of the mid-tones. An often-used application of this is
image being worked on (it becomes darker), while burning-in areas of sky to darken them while
dodging reduces it (a dodged area becomes dodging the foreground. This helps match the sky
brighter). Both techniques change the tonal tones to those of the foreground.
reproduction of the original to correct either errors
or imbalance, or for visual effect. For example, Precision work
the highlights and shadows in any image are low in
contrast, and to counteract this you can burn-in Using the brushes available in all image-
manipulation software, you can apply effects over
as broad an area or with as much precision as you
like—down to the individual pixel, if necessary. You
can adjust brush size—the area over which an effect
is applied—how cleanly the edge of the brush is
defined, and also its “pressure,” or strength of effect.
Some software programs allow you to set “flow,” or
how quickly the effect is applied. The tools should
also allow you to set the tool to limit its effect to the
shadows, mid-tones, or highlights alone.

The Burn and Dodge tools in classic image-
manipulation applications are relatively crude
compared to new tools. Some new brushes can

▶ Correcting tonal
balance

Looking at the original
image (above), the
temptation to burn-in
the foreground and some
of the background in order
to “bring out” the sheep
is irresistible. Brief
applications of the Burn
tool on the foreground (set
to mid-tone at 10 percent)
and background hills, plus
the Dodge tool on the
sheep (set to highlight at
5 percent) produced an
image (right) that was very
similar to the scene as it
appeared at the actual
time of shooting.

BURNING-IN AND DODGING 123

recognize edges and not apply an effect beyond the ▲ Correcting exposure
edge. Others can be set to adjust contrast as well as
brightness when applied. Each tool is perfect for a An exposure biased for a tropical afternoon in Bali,
different task, but you may need more than one Indonesia, rendered the shadows too dark (above left).
software application to find the right tool. By applying to the shadows a Dodging brush set to dodge
mid-tones, a great deal of formerly hidden detail has been
You may also experiment with stronger effects by revealed (above right). Notice that colors emerge richer and
exploiting layer modes such as Color Dodge or brighter. Details in the open area were also burned in
Color Burn (see pp. 180–5). You create a new layer to extract more color from the dull light of the rainy day.
over your image, then apply tints: your choice of
layer mode and layer opacity will control the density HINTS AND TIPS
and contrast of whatever you apply.
▪ Apply dodging and burning-in techniques with
a light touch. Start off by using a light pressure
or a low strength of effect—say, 10 percent
or less—and then build up to the strength
the image requires.

▪ When burning-in image highlights or bright
areas, set the tool to burn-in the shadows
or mid-tones. Do not set it to burn-in the
highlights.

▪ When burning-in mid-tones or shadows, set
the tool at a very light pressure to burn-in the
highlights or mid-tones. Do not set it to
burn-in the shadows.

▪ When dodging mid-tones, set the tool at very
light pressure to dodge the highlights or
mid-tones. Do not set it to dodge the shadows.

▪ When dodging shadows, set the tool to
dodge the highlights. Do not set it to dodge
the shadows.

▪ Use soft-edged or feathered Brush tools to
achieve more realistic tonal results.

124 IMAGE DEVELOPMENT

DUST AND NOISE

Two factors are the “forever enemies” of image Dust-removal options
quality: dust and noise. Dust spots on the image
result when material lands on the photosensor of a Some scanners provide features to mask dust damage,
camera or on film to be scanned. It is a serious replacing the resulting gaps in the image with pixels
problem with SLRs as the debris is recorded on similar to those adjacent to the problem areas. These
every image. Noise—usually seen as pixels markedly can work well, although some may disturb the film’s
different to neighboring pixels and not caused by grain structure, while others work only on color film.
subject features—arises from the electronic
properties of the photosensor of a camera or scanner. Many cameras incorporate mechanisms to
reduce dust, using, for example, rapid vibration to
Noise control shake off particles or antistatic coatings to avoid
attracting particles. Certain SLRs offer dust-removal
You can reduce noise where the noise has a higher software: you photograph a plain surface, have the
frequency than the image detail itself—in other result analyzed by the software, which then creates
words, if the specks are much smaller than the detail a “mask” that can be applied to images to remove
in the image. This is one advantage of increasing the the dust. You can also help the camera directly by
pixel count of images. In low-resolution images, cleaning the sensor using ultrasoft microporous
applying a noise filter smudges image information swabs or ultrafine brushes that sweep up the dust
along with the noise signals. Digital filters such as and reduce static charges.
Noise Ninja are effective at reducing noise only
where required, and all raw converters can reduce Manual removal
noise. DxO Optics stands out by reducing noise
before applying color interpolation. The key image-repair technique is to replace the
dust with pixels that blend in with neighboring
pixels. Depending on your tool of choice, you either

▲ Dust on sensor

A 300 percent enlargement of
the corner of an image shows a
few faint specks of dust. They are
blurred because they lie some
distance above the sensor, which
“sees” only their shadows. However,
with manipulation, the pale spots
will become more visible.

◀ Dust revealed ▲ Dust removed

The full extent of the dust spots Use the Spot Healing Brush, Healing
is revealed when we apply an Brush, or Clone Stamp tool to remove
adjustment layer to increase contrast the dust spots. Set the brush to just
and decrease exposure of the image. slightly larger than the average spot,
This presents the worst-case scenario with a sharply defined brush edge,
and makes it easy to identify and and sweep systematically in
eliminate the spots. one direction.

DUST AND NOISE 125

manually select the source for the pixels to cover
the dust—this is Cloning—or you let the software
sample from around the dust and apply an
algorithm that blends local pixels with the dust to
hide the spots—in Photoshop, this is called Healing.
Where the spots are too numerous, a blurring filter
may help, but this will also blur image detail that is
the same size as the spots.

HINTS AND TIPS ▲ Noise in detail

▪ Clone with the tool set to maximum pressure, In this close-up view of an image, it is clear there is more
as lighter pressure produces a smudged clone. noise, or random pixels (seen as specks and unevenness
of tone), in the darker areas than in the brighter ones.
▪ In even-toned areas, use a soft-edged or Compare the blue shadow area, for example, with the white
feathered Brush as the cloning tool. In areas plate. This is because noise in the photosensor is normally
with fine detail, use a sharp-edge Brush instead. drowned out by higher signals, such as those generated
by strong light.
▪ You do not always have to eliminate dust specks;
reducing their size or contrast may be sufficient.

▪ Work systematically from a cleaned area into areas
with specks, or you may find yourself cloning dust.

▪ If cloning looks overly smoothed, introduce some
noise to make it look more realistic. Select the
area for treatment and then apply the Noise filter.

▲ Noisy image ▲ Screen shots ▲ Smoother but softer

Poor noise-suppression circuitry and Examining the different channels The resulting image offers smoother
an exposure of 1⁄8 sec gave rise to this (above) showed that the noisiest tones—especially skin tones—but the
“noisy” image. Long exposures was the green one. This was cost is visible in reduced sharpness of
increase the chance of stray signals, selected and Gaussian Blur applied the orchids. You could select the red
which increase noise in an image. (top). The radius setting was adjusted and blue channels to apply Unsharp
to balance blurring of the specks Masking to improve the appearance
while retaining overall sharpness. of the flowers.

126 IMAGE DEVELOPMENT ▲ Under-sharpening

SHARPENING In images containing large amounts
of fine detail, such as this scene taken
The ease with which modern image-manipulation in Uzbekistan, applying a modest
software can make a soft image appear sharp is strength of USM filtering (55) and a
almost magical. Although software cannot add to large radius (22), with a threshold set
the amount of information contained in an image, at 11 does little for the image. There
it can put whatever information is there to the best is a modest uplift in sharpness, but
possible use. Edges, for example, can be given more this is due more to an overall increase
clarity and definition by improving local contrast. in contrast rather than any other effect.

Digitally, sharpen effects are true filters, as
they hold back some components and selectively
let others through. A Sharpen filter is, in reality,
a “high-pass” filter—it allows high-frequency image
information to pass while holding back low-
frequency information.

Unsharp Masking

The most versatile method of image sharpening is
Unsharp Masking (USM). This takes a grid of pixels
and increases edge definition without introducing
too many artifacts. Unsharp Mask has three settings.
In Photoshop, they are called Amount, Radius, and
Threshold. Amount defines how much sharpening
to apply; Radius defines the distance around each
pixel to evaluate for a change; Threshold dictates
how much change must occur to be acceptable
and not be masked.

It is possible to overdo sharpening. In general,
assess image sharpness at the actual pixel level, so
that each pixel corresponds to a pixel on the
monitor. Any other view is interpolated and edges
are softened, or anti-aliased, making sharpness
impossible to assess properly.

As a guide, for images intended for print, the
screen image should look very slightly over-
sharpened, so artifacts (such as halos or bright
fringes) are just visible. For on-screen use, sharpen
images only until they look right on the screen.

Sharpening makes deep image changes that
cannot easily be undone, so it is generally best to
leave sharpening to last in any sequence of image
manipulations, except for combining different
layers. However, if you are working on a scan with
many dust specks and other similar types of fault,
you should expect the final sharpening to reveal
more fine defects, so be prepared for another round
of dust removal using cloning (see pp. 124–5).

SHARPENING 127

▲ Over-sharpening ▲ Ideal setting

The maximum strength setting used for The best settings for images with fine
this version results in over-sharpening— detail is high strength with a small
it is still usable and is arguably a good radius and a very low threshold: here,
setting if you intend to print on strength was 222, the radius was 2, and
poor-quality paper. The same setting the threshold was kept at 0. Details are
applied to the Kashgar image (see pp. all well defined and if large-size prints
128–9) would simply bring out all the are wanted, details are crisper than
film grain—a technique for increasing those obtained with sharpening using
noise in the image. a larger radius setting.

128 IMAGE DEVELOPMENT

SHARPENING CONTINUED

▲ Original image ▲ Over-sharpening

This photograph of the main town square in Kashgar, If you increase the sharpening effect
Xinjiang, China, has large areas of smooth tone with (222 in this version) and reduce the
little fine detail, and it would clearly benefit from the threshold (0), but reduce the radius
effects of image sharpening. to 2, virtually everything in the image
increases in sharpness. The result is
HINTS AND TIPS that film grain and fine detail are
sharpened to an undesirable extent.
Using an advanced Photoshop technique for image Compare the result of these settings
sharpening, first mask off areas (such as a face) to with that of an image that contains a
be protected from oversharpening and any mass of fine detail (see p. 126).
associated increase in defects. Next, produce a
duplicate layer of the background and set it to Soft
Light mode. This increases contrast overall. Then
apply the High-Pass filter (found under the Filter
menu in Other > High Pass). Increasing the radius
strengthens the effect (passes higher frequencies, or
more detail). You can now enter Quick Mask mode
or add a layer mask to control which areas of the
image will be sharpened by the High-Pass filter. This
method is also effective for sharpening an image
overall and can be controlled by direct settings and
by opacity. However, the preview window in the
dialogue box does not give an accurate view
because it samples only the top layer.

SHARPENING 129

▲ Sharpening areas of tone ▲ Extreme settings

A moderate amount of sharpening (55) This version results from maximum
and a relatively wide radius for the filter to amount and radius settings. The effect is
act on (22) improves sharpness where there extreme, but a threshold of 32 controls
is subject detail, without bringing out film coloration. Even so, the image has highly
grain or unwanted information, such as in saturated colors and brilliant contrast.
the subject’s skin-tones. A threshold setting In addition, film grain is emphasized. The
of 11 prevents the filter from breaking up random appearance of film grain gives more
smooth tonal transitions, as the sharpening attractive results than the regular structure
effect operates only on pixels differing in of a digital image, so if you want to use
brightness by more than 11 units. this effect introduce image noise first.

130 IMAGE DEVELOPMENT

BLURRING

Blur can be introduced by lowering contrast to give looking through clear, moving water. For some
boundaries a less-distinct outline. This is the subjects this is appropriate, but for blur with some
opposite of sharpening (see pp. 126–9). Paradoxically, clarity, other methods are better. One approach
blurring can make images look sharper; if you throw depends on the data-loss caused by interpolation
a background out of focus, then any detail in front when reducing file sizes. First, increase the image
looks sharper in comparison. size by, say, 300 percent, using Resampling, and
then reduce it to its original size. Check its
Blur options appearance and repeat if necessary. This does take
time, but it can give well-detailed, softly blurred
Blur effects are seldom effective if applied to the results. A quicker, though less-adaptive, method is
whole image, since they often fail to respond to the to reduce the file size, and then increase it, repeating
picture’s content and character. The Median and this step as necessary.
Dust & Scratches filters produce an effect like

▲ Selective blur a special effects, soft-focus lens filter. This type of glass
filter is designed to soften all but a central region of
Although you will not often want to blur an image in the image in order to help concentrate the viewer’s
its entirety, selective blurring, and thus the softening attention on a particular feature. In the example shown
of subject detail, can be extremely useful on occasion. here—an informal portrait of a traveler on a ferry on the
To take one example, the blurred areas of an image River Danube, Hungary—the high-contrast sunlight and
could become the perfect background for typography— the sharpness of background detail was softened to
perhaps on a web page—as the wording would then be emphasize the girl’s features.
easier to read. Another example could be to introduce
digital selective blur to simulate the appearance of using

BLURRING 131

▲ Motion Blur ▲ Dust & Scratches ▲ Radial Blur

This filter simulates the effect of rapid While it is not strictly a blurring filter, Use this filter to apply the blur along
movement across the field of vision. at large radius settings the Dust & lines radiating out from the center of
Usual controls for this filter include Scratches filter does an excellent job the image. This can simulate the effect
altering the angle of the “smear” as of blurring details while retaining of speeding into the distance. For best
well as its length: greater lengths outlines to give a watery effect. results, apply in steps to selectively
suggest higher speed motion. For Setting the Threshold to higher values smaller areas. In Adobe Photoshop,
unusual results apply different angles retains more details. Reduce saturation the filter also offers an option for
to different parts of the image. to create a watercolor look. simulating a zoom blur.

132 IMAGE DEVELOPMENT

BLURRING CONTINUED

Having spent a fortune on lenses that deliver Motion parallax
super-sharp images, it seems madness to introduce
blur into your images. But targeted blur is an Blur is the result of an image moving a visible
essential part of the visual language: it can depict distance across the sensor. As nearby objects appear
movement, it can be used to indicate centers of to move much more than distant objects, even if
interest, and it can imitate effects created by they are actually traveling at the same speed, they
articulated lens movements. The key to targeted always appear more blurred. You see this when
blur is combining masks with blur filters. traveling on a train: the trees nearby are always
blurred, but the mountains in the distance are

CREATING MOVEMENT BLUR

1 Original image 2 Motion Blur
This travel shot is clearly taken in an exotic On a duplicate layer, we apply a Motion Blur
location, but lacks energy and a sense of movement. filter: we line up the motion blur with the long axis of
The four-wheel-drive vehicle looks as though it is the vehicle, adjusting its strength to avoid losing too
stuck in the sand or about to roll backward. We need much detail.
a sense of forward movement.

3 Mask
We now apply a
mask over the majority
of the image—the sky,
the landscape, and the
front of the vehicle. It
now appears that the
exposure time was too
long to capture a sharp
image. But a reality
check will show that this
is a manipulated image:
the difference in
sharpness in the vehicle
gives the game away.

BLURRING 133

sharp. You can simulate this effect by applying blur right-angles to its optical axis. A forward tilt can
to the objects close to the camera while keeping increase apparent depth of field, while a reverse tilt
distant parts of the scene relatively sharp. strongly reduces depth of field, making a scene
resemble a small scale model. The strength of the
Lens movements effect depends on the angle of tilt and the working
aperture set. You can simulate this effect by using
A blur effect that is completely different from graduated masks to control a blur applied to the
motion is created by movement of the lens: this whole image.
means that the lens is articulated so it can rotate at

REVERSE TILT EFFECT

1 High-angle original 2 Quick Mask
Tilt shift gives the impression of a model, so In Quick Mask mode, select the gradient tool,
it works best on shots taken from a high angle, and draw a gradient from the center of the part you want
is effective with objects such as people and cars. This to be in focus to the edges of the image. A few attempts
street scene taken from a hotel window is perfect may be needed to get the right area. The Quick Mask
for this effect. mode allows you to see clearly what will be blurred.

3 Apply blur
Back in standard
mode, the lens blur filter
can be applied; again
this may take a few
attempts to get it right.
You are able to preview
the amount of blur
before you actually
apply it. Although the
effect will look finished
now, using the unsharp
mask filter makes the
people more clearly
defined and adds to
the toy model effect.

134 IMAGE DEVELOPMENT

QUICK FIX IMAGE DISTRACTIONS

Unless there is a fundamental problem with your You could also try desaturating the color: select
image, most minor distractions can be removed, the area of strong color, and lower it using Color
or at least have their pictorial impact reduced, in Saturation to reduce its impact. You can also paint
image-manipulation software. over the color by using the Saturation or Sponge
tool set to desaturate.
Problem: While concentrating on your subject,
Another method is to blur the background
it is easy not to notice distracting objects or colors to render details less visible. This helps push the
in the picture area. This could be anything from a details in the main subject into visual prominence.
passer-by or street litter, to patches of strong color. Select the background directly, or if the main subject
is easier to select, make your selection and invert it.
Analysis: The small viewfinders or screens of Then apply a Blur filter (see pp. 130–1) that is
appropriate to the detail you wish to blur; try
many cameras make it difficult to see much subject different types of blur to evaluate their effect.
detail. Furthermore, although something is distant Select a narrow feather edge to retain sharpness
and looks out of focus, it may still be within the in the subject’s outline. Use caution with strong
depth of field of your set aperture (see pp. 18–21). Blur effects, because the selected region could be
At other times, you simply cannot avoid including, left with a distinct margin.
say, telephone wires in the background of a scene.

Solution: You may not need to remove a HOW TO AVOID THE PROBLEM

distraction completely; simply reducing the Check the viewfinder image carefully before
difference between it and adjacent areas may be shooting. This is easier with SLR cameras and
enough. The usual way to achieve this is with those with large viewfinders. Long focal length
cloning—duplicating part of an image and placing lenses (or zoom settings) reduce depth
it into another part (see pp. 186–7). For example, blue of field and tend to blur backgrounds. And, if
sky can be easily cloned onto wires crossing it, as appropriate to the subject, use a lower viewpoint
long as you are careful to use areas that match and look upward to increase the amount of
in brightness and hue. Clone from as close to the non-distracting sky.
distraction as possible (see also pp. 186–7).

▲ Distracting movement ▲ Cloning

During a shoot in Manila, in the Philippines, the The clean background of one image was first made the

model’s best expression coincided with passers-by in source for the clone. The Clone tool was then very carefully

the background. Fortunately, there were many alternatives aligned with the destination image and the cloned pixels

with a clean background that could be cloned. applied, making the passers-by disappear.

QUICK FIX IMAGE DISTRACTIONS 135

▲ Background distractions ▲ Desaturated elements

In the chaos of a young child’s room, it is neither possible A large, soft-edged Brush tool was chosen, and pressure

nor desirable to remove all the distractions, but toning was set to desaturation at 100 percent and applied to the

them down selectively can help center the viewer’s background. With a lighter setting of 50 percent, the

attention on the main subject. desaturation was also brushed over the clothes.

▲ Selective blur

Despite using a large aperture, the high-contrast blur of
a tree is still obtrusive. By selecting the background and
applying a large blur setting (see right), the impact of the
tree can be reduced. Care needs to be taken to ensure
the model’s face is not blurred and that the fringe
around the model is not left too sharp. You may need
to experiment with different feathering settings (see
pp. 172–5) until you get the best results.

136 IMAGE DEVELOPMENT

WHITE BALANCE

The basis of accurate color reproduction is neutrality may appear harmonious, but may not be color
in the whites, grays, and blacks in the image. When balanced at all.
you ensure these tones are not tinted with colors,
you establish the accuracy of the hues you record. The aim of color balancing is to produce an
The white balance control on digital cameras helps image that appears as if it were illuminated by white
neutralize tints in whites and grays. When you open light; this is achieved by adjusting the white point.
the image, you may take the process further and However, there are different standards for white
adjust other dimensions of color, such as the light, and so there are different white points. For
lightness and saturation. example, it would not look natural to correct an
indoor scene lit by domestic lamps in order to
What balance? make it look like daylight, so a warm-toned white
point is called for instead.
An image that is color balanced is one in which
the illuminating light offers all hues in equal Color Balance control
proportion—in other words, the illumination
is white and not tinted with color. Color This control makes global changes to the standard
balance is not to be confused with color harmony. primary or secondary hues in an image. In some
Thus, a scene can be full of blues or greens yet still software, you can restrict the changes to shadows,
be color balanced, while another scene that features highlights, or mid-tones. This is useful for making
a well-judged combination of secondary colors quick changes to an image that has, for example,
been affected by an overall color cast.

▲ Warm white point DROPPER TOOLS

The original picture of a A quick method of working when you wish to color-correct an image is to
simple still life (above left) decide which part of the picture you want to be neutral—that part you want to
has reproduced with the be seen as without any tint. Then find the mid-tone dropper, usually offered in
strong orange cast that is the Color, Levels, or Curves controls in image-manipulation software. Select the
characteristic of images lit dropper, then click on a point in your image that you know should be neutral.
by domestic incandescent This process is made easier if you used a gray card in one of your images—all
lamps. The corrected images shot under the same lighting as the gray card will require the same
image (above right) was correction. Clicking on the point samples the color data and adjusts the whole
produced using Color image so that the sampled point is neutral: the dropper maps the color data of
Balance. It is still warm all the image pixels around the sampled point.
in tone because a fully
corrected image would
look cold and unnatural.

WHITE BALANCE 137

When working with raw files, the choice of color when shadows on a cloudless day are bluish but
temperature (blue to red) and of tint (green to bright areas are yellowish from the sun. It is
magenta) is yours. Usually, you choose color easiest to work by eye, adjusting until you see the
temperature and tint to ensure neutral (achromatic result you wish for, but for best control you can
or colorless) colors are truly neutral. analyze the color in neutrals and manually put in
corrections to the curve. Working in CMYK, using
Balancing channels Curves gives a great deal of control and the best
results for print. The Color Balance control is
While the Curves control is most often used to essentially a simplified version of using the
adjust image tonality, by altering the Curves or component RGB channels in Curves.
Levels of the individual color channels, you apply a
color balance to the high tones that is different from Channel mixing is effective where a small
that of the shadows. This is helpful, for example, imbalance in the strengths of the component
channels is the cause of color imbalance, due to, for
◀ Original image example, using a colored filter or shooting through
tinted glass.
This original image has
not been corrected in any The Hue/Saturation control can also be used, as
way, and it accurately it shifts the entire range of colors en masse. This can
reproduces the flat be useful when the color imbalance is due to strong
illumination of a solidly coloring of the illuminating light.
cloudy sky.

▲ Color Balance control ▲ Levels control

Strong changes brought about via the Color Balance A golden tone has been introduced to the image here by
forcefully lowering the blue channel in the Levels control—
control, mainly by increasing yellow in the mid-tones— the middle slider beneath the histogram—thus allowing red
and green to figure more strongly. Red and green
which is the lowest slider in the dialog box here—make additively produce yellow, and this color now dominates
the highlights of the image.
the scene look as if it has been lit by an early evening sun.

138 IMAGE DEVELOPMENT

COLOR ADJUSTMENTS

One of the most liberating effects of digital
photography is its total control over color: you can
control effects from the most subtle tints to the
most outrageous color combinations.

Curves

Manipulating Curves, either all at once or as
separate channels, is a potent way to make radical
changes in color and tone. For best results, work in
16-bit color, as steep curve shapes demand the
highest quality and quantity of image data.

Hue/Saturation

This control globally adjusts hues, as well as color
saturation, and brightness. You may also select narrow
ranges of colors to change, thus altering the overall
color balance. Beware of oversaturating colors, as
they may not print out.

Replace Color ▲ Curves control

This replaces one hue, within a “fuzziness” setting or A simple inversion of color and tone leaves dark shadows
wave-band, with another. Select the colors you wish looking empty and blank. Manipulating tonal reproduction
to change by sampling the image with the Dropper via the Curves dialog box, however, gives you more control,
tool, and then transform that part via the Hue/ allowing you to put color into these otherwise empty deep
Saturation dialogue box (see opposite). By setting a shadows (the bright areas after inversion). In the dialog box
small fuzziness factor, you select only those pixels here you can see how the curve runs top left to bottom
very similar in color to the original; a large fuzziness right—the reverse of usual—and the other adjustments that
setting selects relatively dissimilar pixels. It is best to were made to improve density in the image’s mid-tones.
accumulate small changes by repeatedly applying
this control. Replace Color is good for strengthening
colors that printers have trouble with (yellows and
purples), or toning down colors they overdo (reds,
for example).

COLOR TEMPERATURE The color temperature of light is measured
in degrees Kelvin, and a white that is relatively
The color temperature of light has, in fact, nothing yellow in coloration might be around 6,000 K, while
to do with temperature as we traditionally think of a white that is more blue in content might
it; rather, color temperature is measured by be, say, 9,500 K.
correlating it to the color changes undergone
by an object as it is heated. Experience tells us While color slide film must be balanced to a
that cooler objects, such as candles or domestic specific white point, digital cameras can vary their
lights, produce a reddish light, whereas hotter white point dynamically, according to changing
objects, such as tungsten lamps, produce more needs of the situation.
of a blue/white light.

COLOR ADJUSTMENTS 139

▲ Hue/Saturation control ▲ Replace Color control

In this dialog box you can see that image hue has been Four passes of the Replace Color control were made
changed to an extreme value, and this change has been to create an image that is now very different from that
supported by improvements in saturation and lightness in originally captured (see p. 137). The dialog box here shows
order to produce good tonal balance. Smaller changes in the location of the colors selected in the small preview
image hue may be effective for adjusting color balance. window, and the controls are the same as those found in
Bear in mind that colors such as purples look brighter and the Hue and Saturation dialog box (above left), which allow
deeper on a monitor than in print because of limitations in you to bring about powerful changes of color. However, for
the printer’s color gamut. Hue and Saturation to have an effect, the selected values
must indeed have color. If they are gray, then only the
lightness control makes any difference.

WORKING IN RGB to be printed out onto paper, you may think
you should supply your images as CMYK, since
The most intuitive color mode to work in is this is how they will be printed. However, unless
RGB. It is easy to understand that any color you have the specific data or separation tables
is a mixture of different amounts of red, green, supplied by the processors, it is preferable to
or blue, and that areas of an image where full allow the printers to make the conversions
amounts of all three colors are present give you themselves. In addition, CMYK files are larger
white. The other modes, such as LAB and CMYK, than their RGB equivalents and so are far less
have their uses, but it is best to avoid using them convenient to handle.
unless you have a specific effect in mind you want
to achieve. When you are producing image files

140 IMAGE DEVELOPMENT

SATURATION AND VIBRANCE

Technically, saturation is the colorfulness of Saturation
something judged in relation to brightness. Light,
low-saturated colors become darker as they One of the most common enhancements made
increase in saturation, while well-saturated colors to images is an increase in saturation: colors
look brighter and livelier when their saturation is look richer, images look brilliant and, indeed,
raised. This change in quality helps explain why we greatly enhanced. Camera manufacturers
love to make highly saturated images: they look deliberately process images conservatively because
gorgeous on the screen. In image manipulation, oversaturation is hard to recover: variations of hue
Vibrance, rather than meaning “full of energy,” is a take on the same values, so any differences in hue
saturation control that adapts to certain colors. are lost forever. However, global increases
in saturation rarely lead to better images. The most

1 Original 2 High saturation
Young monks in Bhutan chat as they run an Increasing saturation globally renders the
errand on a sunny day—a delightfully photogenic grass rich and lively, and the robes and ropes stand
scene. But overexposure in the capture leads to out in brilliance. But the flesh tones look too tanned,
poor saturation after adjusting Levels. The yellows and notice how the cattle have become more
and reds are acceptable, but the greens are too dull. prominent in the image.

3 High vibrance 4 Minimum vibrance
Returning to the Levels-adjusted original, the If we set minimum vibrance we see that
vibrance setting is increased: the result is a marked colors around flesh tones are reduced to almost
improvement over both the original and the high- grayscale: different applications vary in how strongly
saturation version, with rich colors in the robes they reduce saturation of non-flesh tone colors and
and grass and natural skin tones. the effect also varies with white balance.

SATURATION AND VIBRANCE 141

effective way is to be selective: identify the colors Less-saturated colors increase their saturation
that appear weakest. If you would like a bluer sky, more than the colors that are already saturated.
for example, instead of increasing saturation over Most importantly, Vibrance produces a flatter
the whole image, select Blues in your software’s response with skin tones, which prevents them
saturation control and increase saturation only for from becoming oversaturated. Vibrance is very
blues. The result is powerful, yet subtle. useful for reducing the saturation of other colors
while leaving flesh tones relatively unaltered.
Vibrance The cool pallor that results can be effective in a
wide range of people-based photography—from
The Vibrance control adjusts saturation to minimize fashion to photojournalism.
clipping, that is, loss of definition at high values.

5 Low saturation, high vibrance red-yellow colors closer to their natural levels. The
Combining the two controls can produce difference in saturation helps the flesh tones to stand
highly effective results that balance delicate out against the naturally tinted background. Notice
coloration with a strong sense of realism. If we too how the cattle now “recede” into the background.
set a low saturation, all colors are globally made
grayer. Adding a high vibrance setting restores

142 IMAGE DEVELOPMENT

MANIPULATION DEFECTS

Post-processing techniques are brilliantly powerful. cloning or working with layers. If you are using
But it is good practice to avoid creating unintended direct-working software such as Photoshop, make
defects while making corrections in some other part adjustments on Adjustment Layers where possible,
or aspect of the image. to help preserve quality.

Working methods The majority of images will need only subtle or
soft changes to make a vast improvement to their
Like many other craft skills, post-processing proceeds appearance: these types of change are unlikely to
most smoothly when you work methodically and cause unwanted side effects. It is the application of
steadily. Plan what you want to do with an image strong changes that gives rise to the most problems.
before you start working on it: you will make white One useful trick that may help to reduce side effects
balance, exposure, and tonal adjustments before is to make a series of smaller changes to achieve
tackling deeper changes to the image, such as the same result.

▲ Pixellation ▲ Over-sharpening

The disruption of image detail caused by using too few Sharpening filters such as USM (UnSharp Mask) improve
pixels to create the image is relatively rare, now that the appearance of sharpness but cannot make up for poor
cameras use high-resolution sensors. However, it is possible focusing or blur from movement. High levels of sharpening
to use an icon or low-resolution version of the image by may improve blurred images but at the cost of creating
mistake. Reopen with a larger file. haloes and unnatural tones.

▲ Poor white balance ▲ Cloning or healing defects

Scenes lit by colored lights such as candles or nightclub While cloning and healing tools for removing defects are
spots gain a strong color cast. Even if the overall color cast very powerful, they can introduce defects of their own, such
can be removed to create neutral whites, other colors—such as the blurring of neighboring boundaries and multiplying
as flesh tones—may be inaccurate. Record in RAW (see pp. detail. Work at high magnification—at least 100 percent—
158–61) for the best chance of full correction. and use brushes just larger than the defects.

MANIPULATION DEFECTS 143

Principle of loss DEEP POCKETS

A basic principle of digital photography is that loss A class of image defects, including highlight
of data from an image can never be recovered. clipping, shadow clipping, and banding, can
Many manipulations, from adjusting levels and be avoided by working with the data reserve of
increasing sharpness or blur, to cloning—all destroy RAW format. The data in RAW may be extended
data. In recognition of this, if you are using by outputting the image in high bits per channel.
applications such as Photoshop, Photo Painter, or Instead of the usual 8 bits per channel, RAW
Paint Shop Pro, always work with a copy of the converters allow images to be coded with
image, never the sole image file. If you wish to 10 bits, 12 bits, even 32 bits per channel. This
create a completely new version of an image, open results in large files that are capable of being
up a new copy of the original; do not reuse one that very extensively processed.
has already been heavily manipulated.

▲ Boundaries with haloes ▲ Out-of-gamut colors

Sharpening filters such as USM (UnSharp Mask) and Brilliant colors can be made even more brilliant on
adjustments such as Shadows/Highlights can cause the monitor screen. The result is eye-catching, but some
contrasting bands, or haloes, to appear around edges colors may be impossible to print out, and some may
when used with too high a setting (USM), or too small a lead to solid blocks of color that look unnatural. Use
radius combined with high settings (Shadow/Highlights). the saturation control conservatively (see pp. 140–1).

▲ Banding ▲ Noiseless

Caused by having insufficient data to define smooth In the eagerness to eliminate all signs of noise from the
transitions, banding is seen as stepped changes as the result image, you can cause the image to look too smooth, with
of applying strong tonal change via, for example, Curves, silky textures that blur details. Where detail is near the size
Levels, or Shadow/Highlights controls. It is less of a problem of the noise, for example, the fine wires in this image, noise
than it used to be, thanks to improved sensor processing. reduction also smears the details.

144 IMAGE DEVELOPMENT

CURVES

The Curves control found in image-manipulation The principal difference is that when it comes to
software may remind older photographers of the image-manipulation software the curve is always
characteristic curves published for films. This is a a 45° line at the beginning. This shows that the
graph that shows the density of sensitized material output is exactly the same as the input. However,
that will result from being exposed to specific unlike the film curve, you can manipulate this
intensities of light. In fact, there are similarities, but directly by clicking on and dragging the curve or
equally important are the differences. Both are by redrawing the curve yourself. In this way, you
effectively transfer functions: they describe how force light tones to become dark, mid-tones to
one variable (the input either of color value or of become light, and with all the other variations in
the amount of light) produces another variable (the between. In addition, you may change the curve of
output or brightness of the image). each color channel separately.

▲ Original image and curve ▲ Boosting the mid-tones

Since the original negative was slightly underexposed, The bow-shaped curve displayed here subtly boosts the
the image from the scan is tonally rather lifeless. You mid-tone range of the image, as you can see in the resulting
cannot tell anything about exposure by looking at the image (top). But the price paid is evident in the quarter-
curve in the screen shot (above) because it describes tones, where details in the shadows and the details in the
how one tone is output as another. As nothing has been highlights are both slightly darkened. The result is an image
changed, when it first appears the line is a straight 45°, with, overall, more tonal liveliness—note, too, that the
mapping black to black, mid-tone to mid-tone, and outline of the subject’s face has been clarified. With some
white to white. It is not like a film characteristic curve, image-manipulation software, you have the option of
which actually describes how film is responding to nudging the position of the curve by clicking on the section
light and its processing. you want to move and then pressing the arrow keys up or
down to alter its shape.

CURVES 145

What the Curves control does changes brought about via the Curves control can
be so smooth that the new colors blend seamlessly
The Curves control is a very powerful tool indeed with those of the original.
and can produce visual results that are impossible
to achieve in any other way. By employing less Explore the image by running your cursor over
extreme curves you can improve tones in, for the image: the majority of manipulation software
example, the shadow areas of an image while gives a “running commentary” of color values and
leaving the mid-tones and highlights as they were will also show the position of the point under the
originally recorded. cursor as a point on the curve. Click on the curve
when you hit a tone you wish to alter, then use the
And by altering curves separately by color arrow up/down keys to adjust the position of this
channel, you have unprecedented control over an curve. Make small changes progressively: this helps
image’s color balance. More importantly, the color

▲ Emphasizing the highlights ▲ Emphasizing the shadows

The scan’s flat, dynamic range suggests that it could make The versatility of the original image is evident here, as now
an effective high-key image by changing the curve to it can be seen working as an effective low-key picture. The
remove the black tones (the left-hand end of the curve in mood of the picture is heavier and a little brooding, and it
the screen shot is not on black but is raised to dark gray) has lost its fashion-conscious atmosphere in favor of more
and mapping many highlight tones to white (the top of the filmic overtones. The curve shown in the screen shot has
curve is level with the maximum for nearly a third of the been adjusted not simply to darken the image overall (the
tonal range). The result is that the input mid-tone is set to right-hand end has been lowered to the mid-tone so that
give highlights with detail. Very small changes to the curve the brightest part of the picture is no brighter than normal
can have a large effect on the image, so if you want to mid-tone). In addition, the slight increase in the slope of the
adjust overall brightness, it is easier to commit to the curve curve improves contrast at the lower mid-tone level to
and then use Levels to adjust brightness (see pp. 120–1). preserve some shadow detail. This is crucial, as too many
blank areas would look unattractive.

146 IMAGE DEVELOPMENT

CURVES CONTINUED

ensure you do not make dramatic changes which react best to the application of extreme Curve
look impressive but usually lead to loss of quality. settings are those with simple outlines and large,
obvious features. You can try endless experiments
Extreme curves with Curves, particularly if you start using different
curve shapes in each channel. The following
Curves are also a powerful and simple way to obtain examples show the scope of applying simpler
extreme tonal effects, such as reversal of tones to modifications to the master curve, thereby changing
imitate Sabattier effect. In general, the subjects that

▲ Original image ▲ Reversing dark tones

The image you select for manipulating Curves does not A U-shaped curve reverses all tones darker than mid-tone
have to be of the highest quality, but it should offer a simple and forces rapid changes to occur—an increase in image
shape or outline, such as this church. In addition, the range contrast, for example. The deep shadows in the church
of colors can be limited—as you can see below, dramatic become light areas, giving a negative type of effect, but
colors will be created when you apply Curves with unusual the clouds have darkened and greatly increased in color
or extreme shapes. content. The effect of using this shape curve is similar to
the darkroom Sabattier effect, when exposed film or paper
is briefly reexposed to white light during development.

CURVES 147

all channels at the same time. Note how seemingly smooth tonal transitions, you need access to as
even areas of tone can break up into uneven much image data as possible. Where extreme
patches when an extremely steep curve is applied: adjustments are anticipated, record your images in
this is due to a lack of data, which leads to aliasing RAW format, then convert to RGB applying 16 bits
or posterization. per channel, or even more. With modern high
resolution cameras and image processing, high-bit
The turning point of a curve also places great images are very resistant to breakup of the image.
demand on image data. If you wish to maintain

▲ Reversing light tones ▲ Tone/color reversal

An arc-shaped curve reverses the original’s lighter tones, Applying an M-shaped curve plays havoc with our normal
giving the effect shown here. Although it looks unusual, understanding of what a color image should look like.
it is not as strange as reversing dark tones (left). Note that Not only are the tones reversed as a result, but areas with
the curve’s peak does not reach the top of the range—the dominant color whose tones have been reversed will also
height of the arc was reduced to avoid creating overbright take on a color that is complementary to their own. And
white areas. The color of the building changes as the since parts of the tonal range are reversed and others are
red-green color in the normal image was removed by not, the result is a variegated spread of colors.
the reversal, allowing the blue range to make its mark.

148 IMAGE DEVELOPMENT

COLOR TO BLACK AND WHITE

Creating a black and white picture from a color have. But before you start experimenting, make
original allows you to change the shot’s emphasis. sure you make a copy of your file and work on
For example, a portrait may be marred by strongly that rather than the original. Bear in mind that
colored objects in view, or your subjects may be conversion to black and white loses color data
wearing clashing colored clothing. Seen in black that is impossible to reconstruct.
and white, the emphasis in these pictures is skewed
more toward shape and form. Before you print

The translation process After you have desaturated the image (see box
below), and despite its gray appearance, it is still
A black-and-white image is not a direct translation a color picture. So, unless it is to be printed on a
of colors into grayscale (a range of neutral tones four-color press, you should now convert it to
ranging from white to black) in which all colors grayscale to reduce its file size. If, however, the
are accurately represented—many cameras favor image is to be printed in a magazine or book,
blues, for example, and record them as being lighter remember to reconvert it to color—either RGB or
than greens. CMYK. Otherwise it will be printed solely with black
ink, giving very poor reproduction.
When a digital camera or image-manipulation
software translates a color image, it refers to a built- Four-color black
in table for the conversion. Professional software
assumes you want to print the result and so makes In color reproduction, if all four inks (cyan, magenta,
the conversion according to a regime appropriate yellow, and black) are used, the result is a rich, deep
for certain types of printing press and paper. Other black. It is not necessary to lay down full amounts of
software simply turns the three color channels into each ink to achieve this, but a mixture of all four
gray values before combining them—usually giving inks (called four-color black) gives excellent results
dull, murky results. when reproducing photographs on the printed
page. Varying the ratio of colors enables subtle
There are, however, better ways of converting to shifts of image tone.
black and white, depending on the software you

DESATURATION ▲ Saturation screen shot

All image-manipulation software has a command With the color image open you can access the
that increases or decreases color saturation, or Saturation control and drag the slider to minimum
intensity. If you completely desaturate a color color. This gives a gray image with full color
image, you remove the color data to give just a information. In some software you can desaturate
grayscale. However, despite appearances, it is still the image using keystrokes instead (such as Shift+
a color image and looks gray only because every Option+U in Photoshop, for example).
pixel has its red, green, and blue information in
balance. Because of this, the information is
self-canceling and the color disappears. If, though,
you select different colors to desaturate, you can
change the balance of tones. Converting the image
to grayscale at this point gives you a different result
from a straight conversion, since the colors that you
first desaturate become lighter than they otherwise
would have been.